We continued collaboration with Johns Hopkins Medical Center studying 5 new patients enrolled in the HIV bone marrow transplant study. Sequential virus isolations were done on PBL isolated from these AIDS patients before and after bone marrow transplantation. The patients cells were cultured with normal human blast cells for 4 weeks, sampled weekly & tested for HIV antigen. The following data summarizes the results through 11/90, indicating that there is a trend towards virus reduction after transplantation. The project was temporarily halted for reevaluation and will be continued by Dr.Hana Golding in the Lab of DNA viruses. Studies of the antibody and antigen status of Rhesus monkeys inoculated in 1987 with live HIV-1 virus continued to reveal no antigen being detected, while antibody persisted in the 2 seropositive animals, though at lower levels. A group of Rhesus inoculated in Sept 1988 were also followed during this FY and results indicated that monkeys primed with a gp160 recombinant vaccinia to IIIB and RF viruses followed by 2 boosters with purified gp160 remained seropositive through 95 weeks. A followup study designed to evaluate whether inoculation of IIIB-recombinant vaccinia and 2 boosts with purified gp160 at 2 & 8 months, a different interval than used with the first experiment would either reproduce or maximize the response seen previously. Evaluation of sera through the 5th month indicated that initial inoculation with the vaccinia recombinant induced a better antibody response than initial inoculation with purified gp160. Sequential bleeds from these animals are awaiting analysis. Another study tested a new IIIB gp160 recombinant compared to that used in previous studies and found no antibody response in 6 months when screened on a standard ELISA. Subsequent screening using a purified gp160 ELISA as well as ELISA's specific for antibodies to V3 peptides of IIIB, MN, SF2 and RF strains, indicated low level responses in some of the animals in both groups by the 4th month.